Today's fast-paced cultural climate, combined with the specific needs of certain populations such as, for example, field-deployed military combatants and outdoor recreational enthusiasts, has led to a surge in consumer demand for high-quality non-refrigerated shelf-stable food products that require a minimum of consumer time and effort to prepare. The essential characteristic of shelf-stable food product is that it is not susceptible to the spoilage effects of microorganisms. In order for shelf-stable food products to meet the minimum preparation needs, they should ideally be available to the consumer as pre-cooked and either instantly consumable, or consumable upon heating as through microwaving.
Due to having a moisture content too low to support microbial growth, raw and par-boiled rice are naturally very shelf-stable. Cooking of raw rice is subject to narrow acceptability parameters, and parboiled rice was developed to overcome this disadvantage. Parboiled rice is typically produced by soaking paddy rice and then heating it until gelatinization of the starch in the kernel. This causes many of the nutrients in the husk and bran of the paddy rice to diffuse into the kernel. Dry heat methods of preparation are also known. Convenient preparation of both raw and parboiled rice, however, suffer from the drawback of long cooking times, and parboiled rice, especially brown parboiled rice, takes even longer to cook making it unsuitable for short preparation demands.
The development of pre-cooked dry rice product provide consumers with a more convenient preparation time, but resulted in a reconstituted rice product having an often unacceptable texture and mouth feel.
Canned rice suffered from the disadvantages of discoloration, expensive production, and corrosion of the can by the rice product necessitating relatively high quality cans. Further, canned goods are often negatively perceived by consumers as inferior products. In addition, the canned rice product typically has to be removed from the can and placed into another container before it can be microwaved, diminishing convenience to the consumer.
The development of microwavable retort-pouches comprised of polymeric materials enabled the food industry to economically provide consumers with a commercially sterile rice product that is fully microwavable in its own packaging. Though very convenient with respect to consumer preparation, the rice product itself suffered from texture, mouthfeel and reduced shelf-stability deficiencies. It was discovered that shelf-stability could be enhanced by the addition of acid during processing, but this resulted in the need for additives to mask the acidic taste, and typically the expense of batch processing increased due to the packaging complications and additional steps related to the use of acidic and alkaline compounds.
The current industry-standard batch retort-pouch rice product processing methods result in a pouch-packaged rice product that is not fully hydrated and which only achieves full moisturization upon exposure to steam during consumer preparation, as, for example, during microwaving. Typically, the industry-standard batch processing begins by blanching the rice to partial hydration, for example, to an approximately 1 to 1.1 pick-up of moisture. An oil and flavoring mixture is prepared in a volume of water that is sufficient to fully hydrate the rice and the partially hydrated rice is added to this. However, the watery consistency and very low viscosity of this mixture necessitates the addition of starch and starch emulsifiers, such as lecithin, in order to keep the viscosity at a production-acceptable level and create a rice product that is suitably pumpable according to the standard “liquid fill” method of charging the retort pouches. The starch emulsifiers cause pitting on the surface of the rice grain, resulting in the undesirable batch processing phenomena of “fuzzy rice.”
Under the currently known methods, theoretically, during the thermally sterilizing retort cycle the added heat would allow the rice to cook to complete hydration. However, in reality, as the charged pouches sit through the retort cycle the added starch complexes with some of the flavoring and settles to the bottom of the pouch resulting in an unappealing stratified product.
Across the shelf life of the product, the moisture in the pouch continues to equilibrate with the solid contents of the pouch which results in a hard, brick-like rice product after, typically, only several months. Upon heating by the consumer, a small amount of water steams and puffs the rice product, producing a barely acceptable consistency wherein the rice grains do not have individual identity and are substantially agglomerated. This conventional retort pouch rice product is clearly inferior in consistency, mouth feel and other sensory attributes when compared to consumer expectations of stove-top prepared rice.
Moreover, since the conventional batch processing methods involve the mechanical manipulation and transport of partially hydrated rice, production itself has diminished tolerances. For example, when even minor disruptions occur which stall the processing for longer than several minutes, the partially hydrated rice product is left sitting in manufacturing receptacles, piping and so on, quickly forming a hard, immovable mass that requires expensive and time-consuming production shut-downs to remove.
In addition, acceptable production tolerances permit some percentage, typically about 10% of rice product, to be “left behind” in an “emptied” vessel during certain production steps. Since the rice is only partially hydrated in conventional methods, this additional processing time for approximately 10% of the rice results in rice being charged into the retort pouches and entering the retort cycle in varying states of hydration, which results in a noticeable moisture content inconsistency in the rice when prepared by the consumer.
A further drawback to conventional retort processes which utilize the “liquid fill” method of charging the retort pouch, is the limitation this method places on the inclusion of potentially desirable “chunky” ingredients, for example, meat and other proteinaceous food stuffs.
The present invention seeks to provide a rice product that may be conveniently prepared by consumers, as, for instance, by microwaving, and that comes closer to the mouth feel, appearance and moisture content of what consumers expect from stove-top prepared rice than what is currently available. Specifically, the present invention seeks to provide a retort pouch rice product having substantially individual grain identity with improved consistency and appearance over an extended shelf life when compared to currently available retort pouch rice products. Further, the present invention seeks to provide retort pouch rice products which may optionally include a variety of other desirable chunky ingredients. In addition, the present invention seeks to provide improved batch rice production methods which overcome the aforementioned and other deficiencies in the currently employed state-of-the-art batch rice processing methods.